docs: def format_item(self, item, defaults=None, stencil=None):
          """ Format an item.
          """
          from pyrobase.osutil import shell_escape
  
          try:
              item_text = fmt.to_console(formatting.format_item(self.options.output_format, item, defaults))
          except (NameError, ValueError, TypeError), exc:
              self.fatal("Trouble with formatting item %r\n\n  FORMAT = %r\n\n  REASON =" % (item, self.options.output_format), exc)
              raise # in --debug mode
  
          if self.options.shell:
              item_text = '\t'.join(shell_escape(i) for i in item_text.split('\t'))
  
          # Justify headers according to stencil
          if stencil:
              item_text = '\t'.join(i.ljust(len(s)) for i, s in zip(item_text.split('\t'), stencil))
  
          return item_text